Airplane wing structure



Patented Jan. 27, 1942 I AIRPLANE wmc STRUCTURE Herbert Wagner, Berlin, and Georg Backhaus and Hans Gropler, Dessau, Germany, assignors to Junkers Flugzeug-und-Motorenwerke Aktiengesellschaft, Dessau, Germany, a corporation of Germany Application February 23, 1940, Serial No. 320,406 In Germany December 9, 1938 and the sets of openings 3 and 4, in their relative Claims.

provide a wing structure wherein these two features are so combined that a very material increase in lifting power, specially at steep angles of incidence, may be obtained. so that when starting and landing an airplane may be flown at a very steep angle without losing steerageway, and thus quite small runways and landing flelds may be safely employed.

Having thus briefly stated some of the objects and advantages of the invention 1 will now proceed to describe a preferred embodiment thereof with the aid of the drawing, in which:

Figure 1 illustrates a perspective view of a wing, and 1 Figure 2 is a diagram showing the increase in lifting powerobtained by the use of the invention.

Referring to the drawing, I designates a main wing, and spaced in front thereof is a relatively positions shown, a very marked increase in the lifting capacity of the wing, particularly at steeper angles of incidence, is obtained. As may be seen from the diagram in Figure 2, wherein the full line denotes the lifting capacity with the wing construction as shown, the dotted line indicates the lifting capacity of a wing having no means of influencing the skin layer, n. denotes varying angles of incidence, and ca denotes the coefficient of lifting power,.not only is the lifting power increased under all conditions, but the lifting power continues through greater angles of incidence. This is because air passing upward through the slot 6 reduces the skin layer action of the oncoming air, and effectively increases the lifting power in the front of the wing, and the sets of openings 3 and 4 towards the rear in communication with the passage 5 wherein a suitable pumping or blower arrangement (not shown) is' located permit increase of the lifting power narrow forwardly disposed wing portion 2 so that v a slot 6 is formed between thesaid portion 2 and the main wing I for the passage of air. Thus the skin layer formed by air striking the forwardly disposed wing portion 2 and passing upwardly thereover is blown away from the wing I by air passing upward through the slot 6 and thus diminishing the air resistance to the'front portion of the wing.

Provided in the rear portion of the wing I is a passage 5 having sets of openings 3 and 4 formed therethrough which communicate with the upper skin layer. The openings 3, which are positioned in front of a flap I, and are nearer to the inner extremity of the wing, may either be of uniform size as shown or may be of increasing size from the inner extremity of the wing. The openings 4 are positioned in front of a second flap 8. Within the wins I a conventional pumping or blower arrangement (not shown) is so arranged that it exhausts air from the skin layer through one set of openings and discharges it through the other set.

By the combined arrangement of the slots 2 towards the rear of the wing.

If desired the forwardly disposed auxiliary wing portion 2 may be made adjustable to close the slot 6 or to vary its width of opening. In the present instance this is accomplished by the provision of an axially movable rod I 0 arranged transversely through the wing upon which links I I are pivoted. Extending longitudinally and rearwardly from the wing portion 2 are members I2 the rear extremities of which are also pivoted to the links I I. Thus by movement of the rod III the spacing of the wing portion 2 from the main wing I may be controlled. It is also noted that the auxiliary wing portion 2 may terminate some little distance from the inner extremity of the wing I so that the slot 6 only occurs over the outer wing portion to provide increased lifting capacity over the outer wing portion only.

While in the foregoing the preferred construction has been described and shown, it is understood that the construction is susceptible to such.

within the alterations and modifications as fall scope of the appended claims.

What we claim is:

1. In an arrangement of the character described, the combination with a main wing lying on one side of the fuselage, of a pair of rear flaps associated in laterally juxtaposed relationship with the trailing edge of said main wing, a forwardly disposed wing portion extending longi-- tudinally of the main wing from a point adjacent its outer end along a substantial portion of its length and forming a slot between the upper and lower surfaces thereof, said slot extending well along the wing expanse covered by both flaps, a passage within the wing substantially coextensive and parallel with said slot, a separate openin: from said passage throughthe wing surface adjacent each respective flap, and means within the wing for exhausting air through one of said openings and discharging it through the other.

2. In an arrangement of the character described, the combination with a main'wing lying on one side of the fuselage, of a pair of vrear flaps associated in laterally juxtaposed relationship with the trailing edge of said main wing, a forwardly disposed wing portion extending longitudinally of the main wing from a point adjacent its outer end along a substantial portion of its length and forming a slot between the upper and lower surfaces thereof, said slot extending well along the wing expanse covered by both flaps, a

passage within the wing substantialy coextensive and parallel with said slot, separate openings from said passage. through the upper wing surface adjacent one of said flaps and through the trailing edge of said wing adjacent the other flap, and means within the wing for exhausting air through one opening and discharging it throligh l the other.

3. The arrangement set forth in claim 1 wherein means are provided for varying the width of the forward slot.

4. The arrangement set forth in claim 1 wherein the slot forming forward wing terminates at a point removed from the inner end of the main wing.

5. The arrangement set forth in wherein the passage opening through the trailing edge of the wing is closer to the inside extremity of the latter than the other opening.

\ HERBERT WAGNER. GEORG BACKHAUS. HANS GROPLER. 

